Synthesis And Photoelectrochemical Study On CdSe Nanorod

In this dissertation, CdSe nanorods was prepared by hydrothermal method in different experimental conditions. The photoeleetrochemieal properties of the pure CdSe nanorods and CdSe nanorods modified with poly(3-Methylthiophene)(PMeT) and poly(3-Chlorothiophene)(P3CT)respectively were investigated. The experiment results showed as follows:1)CdSe nanorod was prepared by hydrothermal method, and the products were characterized with TEM,SEM,XRD,TGA-DTA. The results showed that the nanorod was formed approximately with the diameter of 100 nm and the length of 300 nm. The zinc blende structure of CdSe nanorods can be changed into wultize structure when the temperature fised to 240℃; the TGA-DTA and the different sintered temperatures SEM showed that CdSe nanorod/ITO film sintered at 400℃showed better photoelectrochemical properties.2)The CdSe nanorod was prepared into the nanorod structure electrode, the photoelectrochemical properties of the electrode were studied. The maximal incident monochromatic photo-to-current conversion efficiency(IPCE) of the CdSe nanorods by washing with distilled water and absolute ethanol at the 380 nm wavelength was higher than that of the nanorods by washing with distilled water at the 410 nm wavelength. The IPCE for the nanorods sintered at different temperatures was measured, the results showed that the maximum IPCE of wultize CdSe nanorods film electrode reached 74%. Wultize CdSe nanorods maybe was favorable for the IPCE improvement. The CdSe nanorods produced anodic photocurrent, exhibiting the property of the n type semiconductor.3)The CdSe nanorods with different structural phases were prepared by hydrothermal method, and the products were characterized with TEM,SEM,XRD,TGA-DTA. The results showed that the nanorod was formed with zinc blende at 200℃reaction temperature, when the reaction temperature fised to 240℃, the wultize structures CdSe nanorods could be seen.The photoelectrochemical properties of the wultize structure CdSe nanorod was better than that of zinc blende structure CdSe nanorods. The maximal IPCE(80%) of the wultize structure CdSe nanorods film electrode was higher than that of zinc blende structure CdSe nanorods film electrode.4)The photoelectrochemical properties of the CdSe nanorods/PMeT were invest- igated. The PMeT modified CdSe nanorods film electrode, the results showed that it was in the -0.7 V that the Iph had the maximum value. The p-n heterojunction was existed in the CdSe/PMeT film electrode. Photocurrent of PMeT modified CdSe nanorod was higher than CdSe film electrode in long wavelength region.5)The photoeleetrochemieal properties of the CdSe nanorods/P3CT composite film electrode were investigated. The results showed that the maximum value of photocurrent appeared at the—0.6 V electrode potential. The maxium IPCE(39.76%) of modified film electrode was lower than that of(56.84%) CdSe nanorord film electrode. The p-n heterojunetion was existed in the CdSe/P3CT composite film electrode. Because of the existence of p-n heterojunction, under certain condition the IPCE of P3CT modified CdSe nanorod was larger than that of CdSe film electrode in whole long wavelength region (＞410 um).